Vane with spar mounted composite airfoil

ABSTRACT

A vane includes a composite airfoil having one or more pockets and one or more spars received therein respectively. The spars extending radially away from a bridge of a vane mount supporting airfoil. The spars may be integrally formed with the bridge. The spars may be adhesively bonded to the composite airfoil within the pockets. A passage may extend between an airfoil base and an airfoil tip. A gas turbine engine annular fan frame includes an annular row of the composite outlet guide vanes extending radially between and connecting radially inner and outer rings of the fan frame.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to mounting of gas turbine engine compositeairfoils and, particularly, for mounting the airfoils in aircraft gasturbine engines.

2. Description of Related Art

Bypass gas turbine engines of the turbofan type generally includes aforward fan and booster compressor, a middle core engine, and an aft lowpressure power turbine. The core engine includes a high pressurecompressor, a combustor, and a high pressure turbine in a serial flowrelationship. The high pressure compressor and high pressure turbine ofthe core engine are interconnected by a high pressure shaft. The highpressure compressor, turbine, and shaft essentially form the highpressure rotor. The high pressure compressor is rotatably driven tocompress air entering the core engine to a relatively high pressure.This high pressure air is then mixed with fuel in the combustor andignited to form a high energy gas stream. The gas stream flows aft andpasses through the high pressure turbine, rotatably driving it and thehigh pressure shaft which, in turn, rotatably drives the compressor.

The gas stream leaving the high pressure turbine is expanded through asecond or low pressure turbine. The low pressure turbine rotatablydrives the fan and booster compressor via a low pressure shaft, all ofwhich form the low pressure rotor. The low pressure shaft extendsthrough the high pressure rotor. The fan is part of a fan section of theengine and further includes a fan casing surrounding the fan andsupported by a fan frame. Typically, a fan frame includes structural fanstruts radially extending across a fan bypass duct. A forward verticalsupport mount on the fan casing is used to pivotably join and supportthe engine to a pylori on the aircraft and a thrust mount on the framelocated radially inwardly of the bypass duct is used to transfer thrustloads of the engine to the aircraft through the pylori.

The frame may further include fan outlet guide vanes circumferentiallydistributed between the struts that are used to straighten fan airflowexiting the bypass duct. The fan struts and outlet guide vanes aretypically made of metal which are heavier than available compositematerials. Outlet guide vane assemblies are used to remove swirl beforea fan nozzle at the end of a bypass duct. Such outlet guide vaneassemblies are configured to turn the airflow discharged from the fan toa substantially axial direction prior to the fan flow being channeledthrough the bypass duct. In addition to turning the fan airflow, theoutlet guide vane assembly also provides structural stiffness to the fanframe.

It is very desirable to incorporate composite materials in the engine inorder to lower the weight of the engine which provides a more fuelefficient engine and aircraft. It is known to manufacture aircraft gasturbine engine vane airfoils from composite materials. What is furtherdesired are mounting systems for securely and robustly mountingcomposite airfoils in the fan frame assembly that will enhance the lifeof the airfoils and fan frame assembly.

Vanes incorporating composite airfoils especially ones that arestructural vanes, must transfer loads from the composite airfoil tometallic support structure such as the fan frame. In addition to beingstructurally sound it is important for the vane to be low in weight. Itis important to transfer the load from the composite airfoil to themetallic airfoil support structure and to the rest of the fan frame withminimal weight impact.

SUMMARY OF THE INVENTION

A vane comprising includes a composite airfoil having pressure andsuction sides extending outwardly from an airfoil base to an airfoil tipand chordwise spaced apart leading and trailing edges of the compositeairfoil at or near forward and aft ends of the vane. The compositeairfoil is supported by a vane mount which includes one or more sparsextending radially away from a bridge of the vane mount and receivedwithin one or more pockets in the composite airfoil.

The spars may be adhesively bonded to the composite airfoil within theone or more pockets. The composite airfoil may have a passage extendingbetween the airfoil base and the airfoil tip and disposed chordwisebetween the pockets. The spars may be integral with the bridge havingbeen integrally formed with the bridge such as by forging or casting.The vane mount may be an inner vane mount.

A gas turbine engine annular fan frame includes an annular row of thecomposite outlet guide vanes extending radially between and connectingradially inner and outer rings of the fan frame. The outlet guide vanesare mounted in axially extending inner and outer vane mounts attached tothe inner and outer rings respectively. The fan frame may furtherinclude the outer vane mounts attached to an outer fan casing or theouter ring, fairings mounted to and between adjacent ones of the innervane mounts of the outlet guide vanes, and a fan frame flowpath throughthe fan frame extending between the composite airfoils of the outletguide vane and further bounded by the fairings and the outer fan casingor the outer ring.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and other features of the invention are explainedin the following description, taken in connection with the accompanyingdrawings where:

FIG. 1 is a longitudinal part sectional and part diagrammatical viewillustration of an exemplary embodiment of an aircraft turbofan gasturbine engine with a fan frame assembly including outlet guide vaneshaving spar mounted composite airfoils.

FIG. 2 is a perspective view illustration of an outlet guide vaneillustrated in FIG. 1.

FIG. 3 is a partially exploded view illustration of the compositeairfoil and a inner vane mount illustrated in FIG. 2.

FIG. 4 is a perspective view illustration of a couple adjacent outletguide vane illustrated in FIG. 1.

FIG. 5 is an enlarged perspective view illustration of an outer vanemount assembly supporting the composite airfoil illustrated in FIG. 2.

FIG. 6 is an enlarged perspective view illustration of an outlet guidevane mounted between inner and outer rings of the fan frame illustratedin FIG. 1.

FIG. 7 is an enlarged perspective view illustration of an outlet guidevane mounted to an inner ring of the fan frame illustrated in FIG. 1.

FIG. 8 is an enlarged perspective view illustration of an outlet guidevane mounted to a fan outer fan casing of the fan frame illustrated inFIG. 1.

FIG. 9 is a perspective diagrammatical view illustration of an exemplaryembodiment of spars extending radially inwardly from an outer vane mountinto and for support of a composite airfoil.

FIG. 10 is a perspective view illustration of an alternative outer vanemount to mount illustrated in FIG. 9.

DETAILED DESCRIPTION OF THE INVENTION

Illustrated in FIG. 1 is an exemplary aircraft turbofan gas turbineengine 10 circumscribed about an engine centerline axis 12 and suitablydesigned to be mounted to a wing or fuselage of an aircraft. The engine10 includes, in downstream serial flow communication, a fan 14, abooster or a low pressure compressor 16, a high pressure compressor 18,a combustor 20, a high pressure turbine (HPT) 22, and a low pressureturbine (LPT) 24. The HPT or high pressure turbine 22 is joined by ahigh pressure drive shaft 23 to the high pressure compressor 18. The LPTor low pressure turbine 24 is joined by a low pressure drive shaft 25 toboth the fan 14 and booster or low pressure compressor 16.

In typical operation, air 26 is pressurized by the fan 14 and an innerportion of this air is channeled through the low pressure compressor 16which further pressurizes the air. The pressurized air is then flowed tothe high pressure compressor 18 which further pressurizes the air. Thepressurized air is mixed with fuel in the combustor 20 for generatinghot combustion gases 28 that flow downstream in turn through the HPT 22and the LPT 24. Energy is extracted in the two turbines for powering thefan 14, low pressure compressor 16, and the high pressure compressor 18.A flow splitter 34 surrounding the booster compressor 16 immediatelybehind the fan 14 includes a sharp leading edge which splits the fan air26 pressurized by the fan 14 into a radially inner stream channeledthrough the booster compressor 16 and a radially outer stream channeledthrough the bypass duct 36.

A fan nacelle 30 surrounding the fan 14 is supported by an annular fanframe 32. The low pressure compressor 16 is suitably joined to the fan14 forward of the fan frame 32, and is disposed radially inboard of anannular flow splitter 34 spaced radially inwardly from an inner surfaceof the fan nacelle 30 to partially define an annular fan bypass duct 36therebetween. The fan frame 32 is supports the nacelle 30.

The fan frame 32 includes an annular row of composite outlet guide vanes38 (OGVs) extending radially outwardly through the fan bypass duct 36and suitably attached to radially inner and outer rings 33, 35 of thefan frame 32. The composite outlet guide vanes 38 are the onlystructural elements of the fan frame 32 connecting the radially innerand outer rings 33, 35 of the fan frame 32. There are no separatestructural struts of the fan frame 32 passing through the fan bypassduct 36. The outlet guide vanes 38 provide both removal of swirl byturning of the bypass flow in the bypass duct 36 and structuralcapability for the fan frame 32. The outlet guide vanes 38 are mountedto the radially inner and outer rings 33, 35 of the fan frame 32. Theinner and outer rings 33, 35 include forward and aft rails 37, 39illustrated in more detail in FIG. 6.

Referring to FIG. 2, each of the outlet guide vanes 38 is an assemblyincluding a composite airfoil 42 having pressure and suction sides 41,43 extending outwardly from an airfoil base 44 to an airfoil tip 46. Theexemplary pressure and suction sides 41, 43 illustrated herein areconcave and convex respectively. The composite airfoil 42 includeschordwise spaced apart leading and trailing edges LE, TE at or nearforward and aft ends 48, 50 of the outlet guide vane 38. A chord C isdefined as a line between leading and trailing edges LE, TE of anairfoil cross section of an airfoil. A metallic leading edge tip 52 isdisposed along the leading edge LE to protect the composite airfoilagainst foreign object damage (FOD) and bird ingestion damage. Axiallyextending inner and outer vane mounts 54, 56 provide for attaching theoutlet guide vane 38 to the inner and outer rings 33, 35 of the fanframe 32 (illustrated in FIGS. 1 and 6).

The inner vane mount 54 is illustrated herein as but not limited tobeing metallic and includes a bridge 66 extending axially betweenforward and aft flanges 124, 126 depending radially inwardly from theinner vane mount 54 at the forward and aft ends 48, 50 of the outletguide vane 38. The forward and aft flanges 124, 126 are bolted to theforward and aft rails 37, 39 respectively of the inner ring 33 of thefan frame 32. One or more spars extend away from the bridge 66. Theexemplary embodiment of the inner vane mount 54 illustrated in FIGS. 2and 3 include forward and aft spars 70, 72 extending radially away andmore particularly radially outwardly from the bridge 66.

Forward and aft pockets 74, 76 extending radially into the compositeairfoil 42 from the airfoil base 44 are sized and located to receive theforward and aft spars 70, 72 therein respectively as illustrated in FIG.3. The forward and aft spars 70, 72 are adhesively or otherwise bondedor attached to the composite airfoil 42 within the forward and aftpockets 74, 76 respectively. The spars are preferably integral with thebridge 66. The spars may be integrally formed with spar using forging orcasting. The exemplary embodiment of the composite airfoil 42illustrated herein is hollow having a void or a passage 68 extendingfrom the airfoil base 44 to the airfoil tip 46 and disposed chordwisebetween the forward and aft pockets 74, 76.

Illustrated in FIG. 4 is a pair 40 of adjacent outlet guide vanes 38.Each of the outlet guide vanes 38 is an assembly including the compositeairfoil 42. The composite airfoil 42 includes pressure and suction sides41, 43 extending outwardly from an airfoil base 44 to an airfoil tip 46.The exemplary pressure and suction sides 41, 43 illustrated herein areconcave and convex respectively. The composite airfoil 42 includeschordwise spaced apart leading and trailing edges LE, TE at or nearforward and aft ends 48, 50 of the outlet guide vane 38. A chord C isdefined as a line between leading and trailing edges LE, TE of anairfoil cross section of an airfoil. A metal leading edge tip 52 isdisposed along the leading edge LE to protect the composite airfoilagainst foreign object damage (FOD) and bird ingestion damage.

Forward and aft flanges 124, 126 depend radially inwardly from the innervane mount 54 at the forward and aft ends 48, 50 of the outlet guidevane 38 as illustrated in FIGS. 6 and 7. The forward and aft flanges124, 126 are bolted to the forward and aft rails 37, 39 respectively ofthe inner ring 33 of the fan frame 32.

Referring to FIGS. 5, 6, and 8, the outer vane mount 56 is illustratedherein as an assembly of widthwise spaced apart pressure and suctionside brackets 94, 96 that are mounted to pressure and suction sides 100,102 respectively of the composite airfoil 42 at the airfoil tip 46. Thepressure and suction side brackets 94, 96 include pressure and suctionside walls 104, 106 that conform to the shape of the pressure andsuction sides 100, 102 respectively of the composite airfoil 42 at theairfoil tip 46 where the pressure and suction side walls 104, 106 areattached to the airfoil tip 46. Chordwise spaced apart upstream anddownstream ears 110, 112 extend circumferentially or perpendicularlyaway from the pressure and suction side walls 104, 106. The ears arescrewed to the outer fan casing 59 or a shroud in the casing by screwnot illustrated herein. Bolts 107 disposed through correspondingchordwise spaced apart pressure and suction side holes 108, 109 throughthe pressure and suction side walls 104, 106 illustrate herein one typeof means to attach the pressure and suction side walls 104, 106 to theairfoil tip 46.

Referring to FIGS. 4-8, fairings 58 are mounted to and between adjacentinner vane mounts 54 the outlet guide vanes 38. The outer vane mounts 56are attached to an outer fan casing 59 which serves as the outer ring 35of the fan frame 32. The fairings 58 and the fan casing 59 bound andprovide a fan frame flowpath 61 through the fan frame 32 between thecomposite airfoils 42 of the outlet guide vane 38.

Illustrated in FIG. 9 is an axially extending alternative outer vanemount 84 illustrated herein as but not limited to being metallic andincluding an outer bridge 86 extending axially between chordwise spacedapart forward and aft sets 88, 90 of pressure and suction side ears 78,80 extend circumferentially or perpendicularly away from pressure andsuction side surfaces 98, 100 of the outer vane mount 84. The ears arescrewed to the outer fan casing 59 or a shroud in the casing by screwnot illustrated herein.

One or more outer spars extend away from the outer bridge 86. Theexemplary embodiment of the outer vane mount 84 illustrated in FIGS. 9and 10 include forward and aft outer spars 130, 132 extending radiallyaway and more particularly radially inwardly from the outer bridge 86.Forward and aft outer pockets 134, 136 extending radially into thecomposite airfoil 42 from the airfoil tip 46 are sized and located toreceive the forward and aft outer spars 130, 132 therein respectively.The forward and aft outer spars 130, 132 are adhesively or otherwisebonded or attached to the composite airfoil 42 within the forward andaft outer pockets 134, 136 respectively.

The spars are preferably integral with the outer bridge 86. The sparsmay be integrally formed with spar using forging or casting. Theexemplary embodiment of the composite airfoil 42 illustrated herein ishollow having a void or a passage 68 extending from the airfoil base 44to the airfoil tip 46 and disposed chordwise between the forward and aftouter pockets 134, 136.

Illustrated in FIG. 10 is an axially extending alternative low weightouter vane mount 144 with a low weight outer bridge 146 extendingaxially between chordwise spaced apart forward and aft sets 88, 90 ofpressure and suction side ears 78, 80 extend circumferentially orperpendicularly away from pressure and suction side surfaces 98, 100 ofthe outer vane mount 84. While the outer bridge 86 illustrated in FIG. 9has a relatively flat outer surface 97, the outer surface 97 low weightouter bridge 146 is depressed between the forward and aft sets 88, 90 ofpressure and suction side ears 78, 80. The low weight outer bridge 146has a middle section 148 between the forward and aft sets 88, 90 ofpressure and suction side ears 78, 80 that includes a bridge depression150 extending into the middle section 148 and outwardly bounded by thedepressed outer surface 97.

The present invention has been described in an illustrative manner. Itis to be understood that the terminology which has been used is intendedto be in the nature of words of description rather than of limitation.While there have been described herein, what are considered to bepreferred and exemplary embodiments of the present invention, othermodifications of the invention shall be apparent to those skilled in theart from the teachings herein and, it is, therefore, desired to besecured in the appended claims all such modifications as fall within thetrue spirit and scope of the invention.

Accordingly, what is desired to be secured by Letters Patent of theUnited States is the invention as defined and differentiated in thefollowing claims:

1. A vane comprising: a composite airfoil having pressure and suctionsides extending outwardly from an airfoil base to an airfoil tip,chordwise spaced apart leading and trailing edges of the compositeairfoil at or near forward and aft ends of the vane, the compositeairfoil supported by a vane mount, the vane mount including one or morespars extending radially away from a bridge of the vane mount, one ormore pockets disposed in the composite airfoil, and the one or morespars received within the one or more pockets.
 2. A vane as claimed inclaim 1, further comprising the one or more spars adhesively bonded tothe composite airfoil within the one or more pockets.
 3. A vane asclaimed in claim 2, further comprising: a passage in the compositeairfoil, the passage extending between the airfoil base and the airfoiltip, and the passage disposed chordwise between the pockets.
 4. A vaneas claimed in claim 2 further comprising the vane mount includingforward and aft flanges extending radially away from the bridge and theone or more spars at the forward and aft ends of the vane.
 5. A vane asclaimed in claim 1, further comprising the one or more spars beingintegral with the bridge.
 6. A vane as claimed in claim 1, furthercomprising the one or more spars having been integrally formed with thebridge.
 7. A vane as claimed in claim 6, further comprising the one ormore spars having been integrally formed with the bridge by forging orcasting.
 8. A vane as claimed in claim 7, further comprising the one ormore spars adhesively bonded to the composite airfoil within the one ormore pockets.
 9. A vane as claimed in claim 8 further comprising thevane mount including forward and aft flanges extending radially awayfrom the bridge and the one or more spars at the forward and aft ends ofthe vane.
 10. A vane as claimed in claim 9, further comprising the oneor more spars adhesively bonded to the composite airfoil within the oneor more pockets.
 11. A vane as claimed in claim 10, further comprising:a passage in the composite airfoil, the passage extending between theairfoil base and the airfoil tip, and the passage disposed chordwisebetween the pockets.
 12. A vane comprising: a composite airfoil havingpressure and suction sides extending radially outwardly from an airfoilbase to an airfoil tip, chordwise spaced apart leading and trailingedges of the composite airfoil at or near forward and aft ends of thevane, the composite airfoil supported by an inner vane mount, the innervane mount including one or more spars extending radially outwardly froma bridge of the vane mount, one or more pockets disposed in thecomposite airfoil, and the one or more spars received within the one ormore pockets.
 13. A vane as claimed in claim 12, further comprising theone or more spars adhesively bonded to the composite airfoil within theone or more pockets.
 14. A vane as claimed in claim 13, furthercomprising: a passage in the composite airfoil, the passage extendingbetween the airfoil base and the airfoil tip, and the passage disposedchordwise between the pockets.
 15. A vane as claimed in claim 13 furthercomprising the vane mount including forward and aft flanges dependingradially inwardly from the bridge at the forward and aft ends of thevane.
 16. A vane as claimed in claim 12, further comprising the one ormore spars being integral with the bridge.
 17. A vane as claimed inclaim 12, further comprising the one or more spars having beenintegrally formed with the bridge.
 18. A vane as claimed in claim 17,further comprising the one or more spars having been integrally formedwith the bridge by forging or casting.
 19. A vane as claimed in claim18, further comprising the one or more spars adhesively bonded to thecomposite airfoil within the one or more pockets.
 20. A vane as claimedin claim 19, further comprising: a passage in the composite airfoil, thepassage extending between the airfoil base and the airfoil tip, and thepassage disposed chordwise between the pockets.
 21. A vane comprising: acomposite airfoil having pressure and suction sides extending radiallyoutwardly from an airfoil base to an airfoil tip, chordwise spaced apartleading and trailing edges of the composite airfoil at or near forwardand aft ends of the vane, the composite airfoil supported by an innervane mount, the inner vane mount including forward and aft sparsextending radially outwardly from a bridge of the inner vane mount,forward and aft pockets disposed in the composite airfoil, and theforward and aft spars received within the forward and aft pockets.
 22. Avane as claimed in claim 21, further comprising the forward and aftpockets spars adhesively bonded to the composite airfoil within theforward and aft pockets.
 23. A vane as claimed in claim 22, furthercomprising: a passage in the composite airfoil, the passage extendingbetween the airfoil base and the airfoil tip, and the passage disposedchordwise between the pockets.
 24. A vane as claimed in claim 22 furthercomprising the vane mount including forward and aft flanges dependingradially inwardly from the bridge at the forward and aft ends of thevane.
 25. A vane as claimed in claim 21, further comprising the forwardand aft spars being integral with the bridge.
 26. A vane as claimed inclaim 21, further comprising the forward and aft spars having beenintegrally formed with the bridge.
 27. A vane as claimed in claim 26,further comprising the forward and aft spars having been integrallyformed with the bridge by forging or casting.
 28. A gas turbine engineannular fan frame comprising: an annular row of composite outlet guidevanes extending radially between and connecting radially inner and outerrings of the fan frame, each of the vanes including a composite airfoilhaving pressure and suction sides extending outwardly from an airfoilbase to an airfoil tip, the outlet guide vanes mounted in axiallyextending inner and outer vane mounts attached to the inner and outerrings respectively, chordwise spaced apart leading and trailing edges ofthe composite airfoil at or near forward and aft ends of the outletguide vane, the inner vane mount including one or more spars extendingradially away from a bridge of the inner vane mount, one or more pocketsdisposed in the composite airfoil, and the one or more spars receivedwithin the one or more pockets.
 29. A fan frame as claimed in claim 28,further comprising the one or more spars adhesively bonded to thecomposite airfoil within the one or more pockets.
 30. A fan frame asclaimed in claim 29, further comprising: a passage in the compositeairfoil, the passage extending between the airfoil base and the airfoiltip, and the passage disposed chordwise between the pockets.
 31. A fanframe as claimed in claim 30 further comprising a metallic leading edgetip disposed along the leading edge of the composite airfoil.
 32. A fanframe as claimed in claim 31, further comprising the one or more sparsbeing integral with the bridge.
 33. A fan frame as claimed in claim 31,further comprising the one or more spars having been integrally formedwith the bridge by forging or casting.
 34. A gas turbine engine annularfan frame comprising: an annular row of composite outlet guide vanesextending radially between and connecting radially inner and outer ringsof the fan frame, each of the vanes including a composite airfoil havingpressure and suction sides extending outwardly from an airfoil base toan airfoil tip, the outlet guide vanes mounted in axially extendinginner and outer vane mounts attached to the inner and outer ringsrespectively, chordwise spaced apart leading and trailing edges of thecomposite airfoil at or near forward and aft ends of the outlet guidevane, the inner vane mount including forward and aft spars extendingradially away from a bridge of the inner vane mount, forward and aftpockets disposed in the composite airfoil, and the forward and aft sparsreceived within the forward and aft pockets.
 35. A fan frame as claimedin claim 34, further comprising the forward and aft spars adhesivelybonded to the composite airfoil within the forward and aft pockets. 36.A fan frame as claimed in claim 35, further comprising: a passage in thecomposite airfoil, the passage extending between the airfoil base andthe airfoil tip, and the passage disposed chordwise between the pockets.37. A fan frame as claimed in claim 36 further comprising a metallicleading edge tip disposed along the leading edge of the compositeairfoil.
 38. A fan frame as claimed in claim 37 further comprising: theouter vane mounts attached to an outer fan casing or the outer ring,fairings mounted to and between adjacent ones of the inner vane mountsof the outlet guide vanes, and a fan frame flowpath through the fanframe extending between the composite airfoils of the outlet guide vaneand further bounded by the fairings and the outer fan casing or theouter ring.
 39. A fan frame as claimed in claim 37, further comprisingthe forward and aft spars being integral with the bridge.
 40. A fanframe as claimed in claim 39 further comprising: the outer vane mountsattached to an outer fan casing or the outer ring, fairings mounted toand between adjacent ones of the inner vane mounts of the outlet guidevanes, and a fan frame flowpath through the fan frame extending betweenthe composite airfoils of the outlet guide vane and further bounded bythe fairings and the outer fan casing or the outer ring.